cornerstone

American  

[kawr-ner-stohn] / ˈkɔr nərˌstoʊn /

noun

• cornerstones
  plural

1. a stone uniting two masonry walls at an intersection.

2. a stone representing the nominal starting place in the construction of a monumental building, usually carved with the date and laid with appropriate ceremonies.

3. something that is essential, indispensable, or basic.

   The cornerstone of democratic government is a free press.

4. the chief foundation on which something is constructed or developed.

   The cornerstone of his argument was that all people are created equal.

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cornerstone British  

/ ˈkɔːnəˌstəʊn /

noun

1. a stone at the corner of a wall, uniting two intersecting walls; quoin

2. a stone placed at the corner of a building during a ceremony to mark the start of construction

3. a person or thing of prime importance; basis

   the cornerstone of the whole argument

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Other Word Forms

Noun Inflected Forms

• cornerstones
  plural

Etymology

Origin of cornerstone

Middle English word dating back to 1250–1300; see origin at corner, stone

Explanation

A cornerstone is literally a stone at the corner of a building. It’s an important stone, so it also means “the basic part of something,” as in, the cornerstone of the suffragette movement was getting women the right to vote. When a building goes up, putting in the cornerstone is a big deal and people celebrate. Many cornerstones are engraved with historical information about the building, such as the year the building was built. The cornerstone is sometimes made of a different material from the rest of the building too. From the sense of "foundation," cornerstone also means "essential element.” If you’re really into Italian food, you might say that pasta is the cornerstone of your diet.

Example Sentences

See Examples For:

cornerstone cornerstones

“Ride safety is a cornerstone of our business, and when we see guest confidence affected, we take it seriously.”

From Los Angeles Times ● Oct. 13, 2026

France along with Germany is the cornerstone of the euro area, and the euro is the only other reserve currency in the world after the dollar, he noted.

From MarketWatch ● Oct. 1, 2026

Announcing the closure on Tuesday, , external Six Flags Magic Mountain Park President Brian Oerding said: "Ride safety is a cornerstone of our business, and when we see guest confidence affected, we take it seriously."

From BBC ● Sep. 29, 2026

Nepal's hydropower boom has long been touted as a cornerstone of economic growth and renewable energy, but the devastating flood in August exposed its vulnerability.

From Barron's ● Sep. 27, 2026

The Youth League drafted a Program of Action, the cornerstone of which was a campaign of mass mobilization.

From "Long Walk to Freedom" by Nelson Mandela

As tech has grown as an overwhelming force in our lives, the visual design cornerstones associated with it—arial font, minimalist branding, bright colors and clean lines—have become the norm.

From Slate ● Aug. 21, 2026

This devotion to authenticity is one of Thompson’s cornerstones.

From Salon ● May 15, 2026

Homeownership is one of the cornerstones of the American dream, deeply ingrained in our culture as a symbol of financial success and stability.

From MarketWatch ● Apr. 24, 2026

"The UK is setting new standards for online safety. Age checks and risk assessments are cornerstones of our laws, and we'll take robust enforcement action against firms that fall short."

From BBC ● Mar. 19, 2026

Apart from the Suppression of Communism Act, two laws passed in 1950 formed the cornerstones of apartheid: the Population Registration Act and the Group Areas Act.

From "Long Walk to Freedom" by Nelson Mandela

Related Words

• essential
• foundation
• keystone
• linchpin
• mainstay
• pillar